Definition: In this task, you are given an input list A. You need to convert all the alphabets in the list with a number representing their position in the English alphabet. E.g., replace A by 1, B by 2, a by 1, b by 2, and so on.
Input: ['r', 'J', '6855', '6989', 'E', '9087', 'G', '1469']

18, 10, 6855, 6989, 5, 9087, 7, 1469